Corneal crosslinking for pellucid marginal degeneration

Area of Science:

• Ophthalmology
• Corneal Surgery
• Biomedical Engineering

Background:

• Pellucid marginal degeneration (PMD) is a progressive corneal thinning disorder.
• Crab-claw pattern on corneal topography is indicative of PMD.
• Corneal crosslinking (CXL) is a treatment aimed at strengthening corneal tissue.

Purpose of the Study:

• To evaluate the efficacy of corneal crosslinking (CXL) in treating pellucid marginal degeneration (PMD).
• To assess changes in corneal topography and visual acuity after CXL in PMD patients.

Main Methods:

• Retrospective analysis of 808 eyes with a crab-claw pattern on corneal topography.
• Manual measurement of corneal thinnest point (mCTi and mCTs) and calculation of their ratio.
• Corneal crosslinking (CXL) performed on 16 eyes with PMD, followed for 12 months.

Main Results:

• Following CXL, the thinnest corneal point (mCTi) increased over 12 months.
• Inferior corneal curvature (2.5 mm zone) flattened, while central curvature (5.0 mm zone) remained stable.
• Corneal astigmatism decreased, and corrected distance visual acuity (CDVA) improved post-treatment.

Conclusions:

• Manual pachymetric measurements using Scheimpflug imaging are valuable for PMD screening and CXL efficacy evaluation.
• Corneal crosslinking demonstrated a thickening of the thinnest corneal point and flattening of the inferior cornea in PMD patients.